Pavel Karen

Image of Pavel Karen
Norwegian version of this page
Phone +47-22855590
Room ØU 82
Visiting address Sem Sælands vei 26 0371 OSLO
Postal address Postboks 1033 0315 OSLO
Other affiliations Department of Chemistry

Academic interests

  • Inorganic chemistry and crystallography.
  • Metal oxides with fractional valences.
  • Less common combinations of properties: towards halfmetallic ferromagnet.
  • Relationship between structure and phase transitions into valence-controlled states: temperatures of valence mixing, of superconductivity.
  • Less common compositions: carbides-oxides as pseudonitrides, nitrides-fluorides as pseudooxides.
  • Oxide materials with less-common properties: high conductivity, photocatalysis.

Academic interests, methods

  • Syntheses of new compounds at less-common temperature- and redox conditions.
  • Precise valence control in solid oxides of transition metals.
  • Structure determination from synchrotron x-ray and neutron diffraction data.
  • Mössbauer spectroscopy of valence-, spin-, and coordination states (in collaboration).
  • Magnetic, electric and thermal properties of inorganic solids (in collaboration).



  • Positions related to University of Oslo: Professor, lecturer, researcher.
  • Earlier positions: lecturer, University of Chemical Technology, Prague.


  • Textbook of the year, 1987 (University of Chemical Technology, Prague)
  • First place in national Chemistry Olympiad in Prague, 1966

Scientific service

  • IUPAC, titular member in Division II, Inorganic Chemistry
  • IUPAC, member of the Interdivisional Committee on Terminology, Nomenclature and Symbols
  • International Centre for Diffraction Data, a member
  • Norwegian Chemical Society, member of nomenclature committee


An extensive collaboration in Finland and USA


IUPAC project Toward a Comprehensive Definition of Oxidation State

Tags: Inorganic chemistry, Crystallography, Mixed valence


  • Görbitz, Carl Henrik; Karen, Pavel; Dusek, Michal & Petricek, Vaclav (2016). An exceptional series of phase transitions in hydrophobic amino acids with linear side chains. IUCrJ.  ISSN 2052-2525.  3, s 341- 353 . doi: 10.1107/S2052252516010472
  • Karen, Pavel; McArdle, Patrick & Takats, Josef (2016). Comprehensive definition of oxidation state (IUPAC Recommendations 2016). Pure and Applied Chemistry.  ISSN 0033-4545.  88, s 831- 839 . doi:
  • Gorbitz, Carl Henrik & Karen, Pavel (2015). Twin displacive phase transitions in amino acid quasiracemates. Journal of Physical Chemistry B.  ISSN 1520-6106.  119(15), s 4975- 4984 . doi: 10.1021/acs.jpcb.5b01483
  • Karen, Pavel (2015). Oxidation state, a long-standing issue!. Angewandte Chemie International Edition.  ISSN 1433-7851.  54(16), s 4716- 4726 . doi: 10.1002/anie.201407561
  • Jantsky, Laurent; Okamoto, Hiroshi; Thomas, Michael; Karen, Pavel; Hauback, Bjørn; Rosseinsky, Matthew J & Fjellvåg, Helmer (2014). Complex Magnetic Behavior in the PrSr3(Fe1–xCox)3O10−δ n = 3 Ruddlesden–Popper-Type Solid Solution with High Valent Cobalt and Iron. Chemistry of Materials.  ISSN 0897-4756.  26(2), s 886- 897 . doi: 10.1021/cm400394c
  • Karen, Pavel; McArdle, Patrick & Takats, Josef (2014). Toward a comprehensive definition of oxidation state (IUPAC Technical Report). Pure and Applied Chemistry.  ISSN 0033-4545.  86(6), s 1017- 1081 . doi: 10.1515/pac-2013-0505
  • Lindé, Johan Kaarle Mikael; Lindroos, F. & Karen, Pavel (2014). Iron orbital occupancies upon valence mixing of charge-ordered GdBaFeIIFeIIIO5. Hyperfine Interactions.  ISSN 0304-3843.  226(1-3), s 329- 339 . doi: 10.1007/s10751-013-0973-8
  • Olsen, Jørn Eirik; Karen, Pavel; Sørby, Magnus Helgerud & Hauback, Bjørn (2014). Effect of chloride substitution on the order-disorder transition in NaBH4 and (NaBD4)-B-11. Journal of Alloys and Compounds.  ISSN 0925-8388.  587, s 374- 379 . doi: 10.1016/j.jallcom.2013.10.171 Full text in Research Archive
  • Lindén, J. & Karen, Pavel (2012). Modeling hyperfine parameters observed from the charge-ordered to valence-mixed state of NdBaFe2O5. Journal of Physics: Condensed Matter.  ISSN 0953-8984.  24(37) . doi: 10.1088/0953-8984/24/37/376002
  • Linden, J & Karen, Pavel (2010). NdBaFe2O5+w and steric effect of Nd on valence mixing and ordering of Fe. Journal of Solid State Chemistry.  ISSN 0022-4596.  183(11), s 2703- 2713 . doi: 10.1016/j.jssc.2010.09.012
  • Andersson, K. Kristoffer & Karen, Pavel (2009). Mössbauer Spectroscopy in the Nordic countries; University of Oslo. Mössbauer Effect Reference and Data Journal.  ISSN 0163-9587.  32(1), s 34- 36
  • Seibel, HA; Karen, Pavel; Wagner, TR & Woodward, PM (2009). Synthesis and characterization of color variants of nitrogen- and fluorine-substituted TiO2. Journal of Materials Chemistry.  ISSN 0959-9428.  19(4), s 471- 477 . doi: 10.1039/b815758h
  • Woodward, PM; Goldberger, J; Stoltzfus, MW; Eng, HW; Ricciardo, RA; Santhosh, PN; Karen, Pavel & Moodenbaugh, AR (2008). Electronic, magnetic, and structural properties of Sr2MnRuO6 and LaSrMnRuO6 double perovskites. Journal of The American Ceramic Society.  ISSN 0002-7820.  91, s 1796- 1806 . doi: 10.1111/j.1551-2916.2008.02412.x
  • Chang, S; Karen, Pavel; Hehlen, MP; Trouw, FR & McQueeney, RJ (2007). Damping of antiferromagnetic spin waves by valence fluctuations in the double layer perovskite YBaFe2O5. Physical Review Letters.  ISSN 0031-9007.  99 . doi: 10.1103/PhysRevLett.99.037202
  • Karen, Pavel; Gustafsson, K & Linden, J (2007). EuBaFe2O5: Extent of charge ordering by Mossbauer spectroscopy and high-intensity high-resolution powder diffraction. Journal of Solid State Chemistry.  ISSN 0022-4596.  180
  • Karen, Pavel; Gustafsson, K & Linden, J (2007). EuBaFe2O5+w: Valence mixing and charge ordering are two separate cooperative phenomena. Journal of Solid State Chemistry.  ISSN 0022-4596.  180, s 148- 157 . doi: 10.1016/j.jssc.2006.09.031
  • Karen, Pavel (2006). Nonstoichiometry in oxides and its control. Journal of Solid State Chemistry.  ISSN 0022-4596.  179, s 3167- 3183
  • Karen, Pavel; Moodenbaugh, AR; Goldberger, J; Santhosh, PN & Woodward, PM (2006). Electronic, magnetic and structural properties of A(2)VMoO(6) perovskites (A = Ca, Sr). Journal of Solid State Chemistry.  ISSN 0022-4596.  179
  • Linden, J; Karen, Pavel; Nakamura, J; Karppinen, M & Yamauchi, H (2006). Transport and magnetotransport properties across the two-step Verwey transition in BaGdFe2O5+w. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  73
  • Karen, Pavel; Suard, Emmanuelle & Fauth, Francois (2005). Crystal Structure of Stoichiometric YBa2Fe3O8. Inorganic Chemistry.  ISSN 0020-1669.  44, s 8170- 8172
  • Karen, Pavel; Suard, Emmanuelle; Fauth, Francois & Woodward, Patrick M. (2004). YBaMnCoO5; neither valence mixed nor charge ordered. Solid State Sciences.  ISSN 1293-2558.  6(11), s 1195- 1204
  • Lindén, Johan; Karen, Pavel; Yamauchi, Hisao & Karppinen, Maarit (2004). Exploring the Verwey-Type Transition in GdBaFe2O5+w Using 57Fe Moessbauer Spectroscopy. Hyperfine Interactions.  ISSN 0304-3843.  156/157(1-4), s 321- 325
  • Lindén, Johan; Karen, Pavel; Yamauchi, Hisao & Karppinen, Maarit (2004). Valence mixing, separation and ordering in double-cell perovskite GdBaFe2O5+w. Journal of Magnetism and Magnetic Materials.  ISSN 0304-8853.  272-276, s E267- E268
  • Karen, Pavel (2004). Chemistry and thermodynamics of the twin charge-ordering transitions in RBaFe2O5+w series. Journal of Solid State Chemistry.  ISSN 0022-4596.  177, s 281- 292
  • Moritomo, Y; Hanawa, M; Xu, S; Ishikawa, H; Ohishi, Y; Kato, K; Honma, T; Karen, Pavel; Karppinen, M & Yamauchi, H (2004). Pressure effects on the charge-ordering transition of BaYCo2O5.0. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  69, s art. no.- 134118
  • Nakamura, J; Karppinen, M; Karen, Pavel; Linden, J & Yamauchi, H (2004). Isovalent-substitution effect on the Verwey-type transition in the A-site-ordered double perovskite (Ba,Sr)RFe2O5. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  70
  • Huang, Q. Z.; Karen, V. L.; Santoro, A.; Kjekshus, Arne; Lindén, Johan; Pietari, T. & Karen, Pavel (2003). Substitution of Co3+ in YBa2Fe3O8. Journal of Solid State Chemistry.  ISSN 0022-4596.  172, s 73- 80
  • Karen, Pavel (2003). Effects of oxygen nonstoichiometry and of its distribution on Verwey-type transitions and structure of GdBaFe2O5+w. Journal of Solid State Chemistry.  ISSN 0022-4596.  170, s 9- 23
  • Karen, Pavel; Kjekshus, Arne; Huang, Q.; Karen, V. L.; Lynn, J. W.; Rosov, N.; Natali Sora, I. & Santoro, A. (2003). Neutron powder diffraction study of nuclear and magnetic structures of oxidized and reduced YBa2Fe3O8+w. Journal of Solid State Chemistry.  ISSN 0022-4596.  174, s 87- 95
  • Woodward, Patrick M. & Karen, Pavel (2003). Mixed valence in YBaFe2O5. Inorganic Chemistry.  ISSN 0020-1669.  42(4), s 1121- 1129
  • Woodward, Patrick M.; Suard, Emmanuelle & Karen, Pavel (2003). Structural tuning of charge, orbital, and spin ordering in double-cell perovskite series between NdBaFe2O5 and HoBaFe2O5. Journal of the American Chemical Society.  ISSN 0002-7863.  125, s 8889- 8899
  • Karen, Pavel; Woodward, Patrick M.; Santhosh, P.N.; Vogt, Tom; Stephens, P.W. & Pagola, S. (2002). Verwey transition under oxygen loading in RBaFe2O5+w (R = Nd and Sm). Journal of Solid State Chemistry.  ISSN 0022-4596.  167, s 480- 493
  • Karen, Pavel; Woodward, Patrick M.; Lindén, Johan; Vogt, Tom; Studer, Andrew & Fischer, Peter (2001). Verwey transition in mixed-valence TbBaFe<SUB>2</SUB>O<SUB>5</SUB>: Two attempts to order charges. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  64(21), s 214405/1- /14
  • Karen, Pavel; Kjekshus, Arne; Huang, Q.; Karen, V. L.; Mighell, A. D. & Santoro, A. (2000). Neutron powder diffraction study of the crystal structure of the oxycarbonate phase YBa2Cu2.85(CO3)0.15O6.73. Physica. C, Superconductivity.  ISSN 0921-4534.  336, s 279- 286
  • Vogt, Tom; Woodward, Patrick M.; Karen, Pavel; Hunter, B.A.; Henning, P. & Moodenbaugh, A.R. (2000). Low to High Spin-State Transition Induced by Charge Ordering in Antiferrimagnetic YBaCo2O5. Physical Review Letters.  ISSN 0031-9007.  84(13), s 2969- 2972
  • Karen, Pavel; Kjekshus, Arne; Huang, Q. & Karen, V. L. (1999). The Crystal Structure of Magnesium Dicarbide. Journal of Alloys and Compounds.  ISSN 0925-8388.  282, s 72- 75
  • Karen, Pavel & Woodward, Patrick M. (1999). Synthesis and Structural Investigations of the Double Perovskites REBaFe<SUB>2</SUB>O<SUB>5+w</SUB> (RE = Nd, Sm). Journal of Materials Chemistry.  ISSN 0959-9428.  9, s 789- 797
  • Lindén, Johan; Karen, Pavel; Kjekshus, Arne; Miettinen, J. & Karppinen, Maarit (1999). Partial Oxygen Ordering in Cubic Perovskite REBa<SUB>2</SUB>Fe<SUB>3</SUB>O<SUB>8+w</SUB> (RE= Gd, Eu, Sm, Nd). Journal of Solid State Chemistry.  ISSN 0022-4596.  144, s 398- 404
  • Lindén, Johan; Karen, Pavel; Kjekshus, Arne; Miettinen, J.; Pietari, T. & Karppinen, Maarit (1999). Valence State Mixing and Separation in SmBaFe<SUB>2</SUB>O<SUB>5+w</SUB>. Physical Review B. Condensed Matter and Materials Physics.  ISSN 1098-0121.  60(22), s 15251- 15260

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  • Karen, Pavel & Benneche, Tore (2004). KJM1010 Kjemiske strukturer og prinsipper - Laboratoriekurs. Universitetet i Oslo, Reprosentralen.  81 s.
  • Karen, Pavel & Furuseth, Sigrid Breien (2004). KJM1010 Kjemiske strukturer og prinsipper - Tilleggskompendium: Konsepter i uorganisk reaksjonskjemi. Universitetet i Oslo, Reprosentralen.  24 s.

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  • Karen, Pavel (2008). KJM 1120 Uorganisk kjemi Laboratoriekurs hoestsemester 2008.
  • Karen, Pavel (2008). Most pressurized elements aren't simple cubic. Physics today.  ISSN 0031-9228.  61, s 10- 10
  • Karen, Pavel (2008). Valence mixing and ordering in RBaFe2O5+w.
  • Karen, Pavel (2007). KJM1030 Uorganisk kjemi Laboratoriekurs, vårsemester 2007.
  • Karen, Pavel (2007). Valence-mixed compounds (Fe3O4 and RBaFe2O5).
  • Karen, Pavel (2006). KJM1030 Uorganisk kjemi, Laboratoriekurs, vårsemester 2006.
  • Karen, Pavel (2006). KJM1021 Kjemisk Struktur og Reaktivitet, Laboratoriekurs uorganisk del høstsemesteret 2006.
  • Karen, Pavel (2005). Nonstoichiometry in oxides and its control.
  • Karen, Pavel (2005). Verwey transition in a perovskite-type structure.
  • Karen, Pavel (2005). What is Verwey transition and why it may matter.
  • Karen, Pavel (2004). Tuning the Verwey transition as an orbital ordering, ILL Annual Report 2003, p.24-5 .
  • Karen, Pavel (2004). What RBaFe2O5+w tells us about Verwey transition and why it matters .
  • Karen, Pavel (2002). Charge ordering that only succeeds after nature's second attempt.
  • Karen, Pavel (2002). KJ 102 Uorganisk kjemi, Laboratoriekurs, høstsemester 2002.
  • Karen, Pavel; Woodward, Patrick M. & Lindén, Johan (2002). Charge ordering that only succeeds after nature's second attempt.
  • Karen, Pavel (2001). KJ110 Uorganisk kjemi I; Laboratoriekurs, høstsemester 2001.
  • Karen, Pavel (2000). KJ 110 Uorganisk kjemi I; Laboratoriekurs, høstsemester 2000.
  • Karen, Pavel & Kjekshus, Arne (2000). Phase Diagrams and Thermodynamic Properties, In Karl A. Jr. Gschneidner; LeRoy Eyring & Brian M. Maple (ed.),  Handbook on the Physics and Chemistry of the Rare Earths. Volume 30, High-Temperature Superconductors - I.  Elsevier Science B.V., The Netherlands.  ISBN 0-444-50528-8.  s 229 - 373
  • Lindén, Johan; Nakamura, Jin; Karen, Pavel; Kjekshus, Arne; Karppinen, Maarit & Yamauchi, Hisao (2000). Observation of mixed-valence state in the BaSm(Cu1-xFex) phase.
  • Karen, Pavel (1999). Ordering, Mixed-Valence and Metallic Character Along the Redox Range in LnBaM<SUB>2</SUB>O<SUB>5+w</SUB> (M = Fe and Co).

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Published Nov. 11, 2010 9:00 AM - Last modified Apr. 15, 2016 9:50 AM